If a street is marked with a do not enter sign, what does that mean?

Answer: C — You must not enter the marked street

When a street is marked with a "Do Not Enter" sign, it explicitly indicates that drivers are prohibited from entering that specific roadway. This sign is used to enhance safety by preventing vehicles from entering streets that may be one-way in the opposite direction or where entering could create a hazardous situation. Understanding the implications of this sign is crucial for maintaining traffic flow and ensuring safety for all road users. It's important to adhere to these signs because entering a restricted area can lead to accidents and disrupt the normal flow of traffic. Being aware of such signage demonstrates responsible driving behavior and compliance with traffic regulations.